Reversible fiber optic connector

ABSTRACT

A re-terminable, no-crimp ST-type optical connector assembly includes a spring-loaded ferrule holder assembly and a reusable activation system for termination of the assembly. The optical connector can be terminated by a suitable cam activation tool. The connector includes a housing, such as a bayonet, matable to a mating adapter, a backbone retained within a rear of the housing, a ferrule holder provided within the backbone, and a cam provided between the ferrule holder and the backbone. The ferrule holder includes an alignment key exposed to mate with a cam activation tool to lock rotation of the ferrule holder relative to other connector components. The cam includes a cam activation cutout at a front face thereof that mates with a cam activation tool interface to enable rotation of the cam between de-activated and activated positions, the cam activation cutout also receiving the alignment key of the ferrule holder therethrough. The cam further includes a first camming profile that actuates a field fiber clamp and a second camming profile that actuates a buffer clamp. The connector may further include alignment flats and features for preventing rotation and axial movement of various components. Because the cam is unexposed when mated, inadvertent de-activation is prevented.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/697,905, filed Feb. 1, 2010, which is a continuation of U.S.application Ser. No. 11/761,756, filed Jun. 12, 2007, which issued asU.S. Pat. No. 7,654,748 on Feb. 2, 2010, which is a continuation of U.S.application Ser. No. 11/423,817, filed Jun. 13, 2006, which issued asU.S. Pat. No. 7,241,056 on Jul. 10, 2007, the subject matter of which ishereby incorporated herein by reference in its entirety.

BACKGROUND

1. Field of Invention

A re-terminable, no-crimp ST-type optical connector assembly includes aspring-loaded ferrule holder assembly and a reusable activation systemfor termination of the assembly. The optical connector can be terminatedby a suitable cam activation tool.

2. Description of Related Art

Fiber optic networks are becoming increasingly commonplace intelecommunications applications due to their increased bandwidth anddistance capabilities relative to copper networks. However, compared tocopper systems, fiber optic cables and connections are well known fortheir more critical and difficult termination.

Alignment between abutted glass cores within a fiber optic interface iscrucial to the performance of the connection. Additionally, fieldinstallation of standard “pot and finish” fiber optic connectors isextremely labor and expertise intensive. In most applications, aninstaller is required to prepare a fiber end, glue the fiber end in theconnector, cleave the excess fiber from the end face of the connector,and polish the end face of the connector to obtain the optimum geometryfor optical performance. End face polishing is a difficult andtime-consuming step, particularly when using single mode fiber, whichachieves its best performance when using an automated polishing machine.However, automated polishing machines are often large and expensive,rendering them impractical for field use.

Fiber pigtails connectors eliminate the need for such lengthy steps andare factory prepared with a length of fiber. However, these require afusion splicing machine and protective sleeve, which are expensive.

Fiber stub connectors were designed to eliminate the need for fusionsplicing equipment and lengthy termination steps. The fiber stub employsa short fiber stub that is spliced to the field fiber within theconnector. Stub connectors typically require a crimp to activate thesplice or retain the field fiber, or both. However, the crimpingoperations, whether occurring at the interface point or some other pointto retain the field fiber, have a tendency to pull the field fiber andstub fiber apart, or otherwise damage the signal passing function of theinterface.

Moreover, if the connection is found to be poor after crimping, theconnection must be cutoff because crimping is most often an irreversibleoperation. This wastes a stub fiber connector and a length of fiberoptical cable and requires a new connector and fiber optical cable endto be terminated.

Recently reusable or re-terminable fiber stub connectors have beendeveloped, such as that disclosed in commonly assigned U.S. applicationSer. No. 10/647,848 filed Aug. 25, 2003, the subject matter of which ishereby incorporated herein by reference in its entirety. Another knownreusable or re-terminable fiber stub connector is disclosed in commonlyassigned U.S. application Ser. No. 11/262,660, the subject matter ofwhich is also hereby incorporated herein by reference in its entirety.

Because of the small size of such re-terminable connectors, it is oftendifficult to terminate such connectors in the field. Moreover, it waspossible in prior designs for the connector to become accidentallyde-activated during use.

SUMMARY

There is a need for a re-terminable fiber-optic connector assembly thatcan readily and positively terminate a re-terminable fiber stubconnectors in the field.

Advantageous features are a re-terminable fiber optic connector assemblyhaving an internal cam mechanism that can terminate the fiber stubthrough relative rotation of at least one part of the connector assemblyrelative to another. The activation may be achieved using a hand-heldcam activation tool, or used in conjunction with a connector supportstructure to provide simplified and expeditious field termination offiber optic cables.

In exemplary embodiments, the re-terminable connector is an ST-typeconnector.

In accordance with other aspects of the invention, the connectorincludes a housing, such as a bayonet, matable to a mating adapter, abackbone retained within a rear of the housing, a ferrule holderprovided within the backbone, and a cam provided between the ferruleholder and the backbone. Preferably, the ferrule holder includes analignment key exposed to mate with a cam activation tool to lockrotation of the ferrule holder relative to other connector components.

In an exemplary embodiment, the cam includes a cam activation cutout ata front face thereof that mates with a cam activation tool interface toenable rotation of the cam between de-activated and activated positions,the cam activation cutout also receiving the alignment key of theferrule holder therethrough. The cam further includes a first cammingprofile that actuates a field fiber clamp and a second camming profilethat actuates a buffer clamp.

In accordance with other aspects of the invention, the connector mayfurther include alignment flats and features for preventing rotation andaxial movement of various components.

In accordance with yet additional aspects, because the cam is unexposedwhen mated, inadvertent de-activation can be prevented.

Other features and advantages will be recognized when read in light ofthe following disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments will be described in detail, withreference to the following figures, wherein:

FIG. 1 shows an exploded view of an exemplary pre-polished no crimpfiber optic connector;

FIG. 2 shows an assembled perspective view of the fiber optic connectorof FIG. 1;

FIG. 3 shows a cross-sectional view of the optical connector of FIG. 2taken along the centerline (with the strain relief boot omitted);

FIG. 4 shows a perspective partial cross-sectional view of a feruleholder in the optical connector of FIG. 1;

FIG. 5 shows a perspective view of an exemplary cam of the opticalconnector of FIG. 1;

FIG. 6 shows a cross-sectional view of the cam of FIG. 5 taken along thecenterline;

FIG. 7 shows a cross-sectional view of the cam of FIG. 6 taken alonglines 7-7;

FIG. 8 shows a cross-sectional view of the cam of FIG. 6 taken alonglines 8-8;

FIG. 9 shows a perspective partial cross-sectional view of an exemplarybayonet of the optical connector of FIG. 1;

FIG. 10 shows a perspective view of an exemplary backbone of the opticalconnector of FIG. 1;

FIG. 11 shows a backside perspective partial cross-sectional view of thebackbone of FIG. 10;

FIG. 12 shows a perspective view of an exemplary retaining nut of theoptical connector of FIG. 1;

FIG. 13 shows a perspective view of an exemplary cam plank of theoptical connector of FIG. 1;

FIG. 14 shows a perspective view of an exemplary Vee-plank of theoptical connector of FIG. 1;

FIG. 15 shows a perspective view of an exemplary ferrule of the opticalconnector of FIG. 1;

FIG. 16 shows an exemplary optical fiber stub of the optical connectorof FIG. 1;

FIG. 17 shows exemplary strain relief boots of the optical connector ofFIG. 1;

FIG. 18 shows an exploded perspective view of a ferrule holdersub-assembly of the optical connector of FIG. 1 prior to assembly;

FIG. 19 shows a perspective view of the ferrule holder sub-assembly ofFIG. 18 in an assembled state;

FIG. 20 shows an exploded perspective view of a cam sub-assembly of theoptical connector of FIG. 1 prior to assembly;

FIG. 21 shows a perspective view of the cam sub-assembly of FIG. 20 inan assembled state;

FIG. 22 shows an exploded perspective view of the assembled ferruleholder sub-assembly and cam sub-assembly;

FIG. 23 shows a perspective view of the sub-assemblies of FIG. 22 onceassembled;

FIG. 24 shows a cross-sectional view of the internal cam of the opticalconnector in a non-activated position;

FIG. 25 shows a cross-sectional view of the internal cam of the opticalconnector in a partially activated position;

FIG. 26 shows a cross-sectional view of the internal cam of the opticalconnector in a fully activated position;

FIG. 27 shows an exploded perspective view of a cam activation tool base1 and cam activation tool 2 according to an exemplary embodiment;

FIG. 28 shows a perspective view of the cam activation tool base 1 ofFIG. 27;

FIGS. 29-30 show front and rear perspective views of the cam activationtool 2 of FIG. 27;

FIGS. 31-33 show perspective views of cam activation tool assembly, inwhich FIG. 31 shows cam activation tool 2 approaching base 1, FIG. 32shows a front view of cam activation tool 2 installed onto base 1, andFIG. 33 shows a rear view of cam activation tool installed onto base 1;

FIGS. 34-35 show installation of a re-terminable fiber optic connectoronto the cam activation tool assembly;

FIG. 36 shows an installed re-terminable fiber optic connector in thecam activation tool assembly with the cam activation tool located in afirst position;

FIG. 37 shows the installed re-terminable fiber optic connector in thecam activation tool assembly with the cam activation tool located in arotated second position;

FIG. 38 shows the installed re-terminable fiber optic connector in thecam activation tool assembly of FIG. 37 with the connector bayonet andspring removed to show internal parts;

FIG. 39 shows the installed re-terminable fiber optic connector in thecam activation tool assembly of FIG. 38 with the connector bayonet andspring removed to show internal parts when the cam activation tool islocated in the second position;

FIG. 40 shows the installed re-terminable fiber optic connector in thecam activation tool as part of an Opti-Cam termination tool;

FIG. 41 shows a perspective view of an exemplary bayonet for an ST-typefiber optic connector according to a further embodiment of theinvention;

FIG. 42 shows a partial cross-sectional view of the bayonet of FIG. 41;

FIG. 43 shows a perspective view of an exemplary fiber optic connectorof the ST-type with the bayonet of FIG. 41 and a strain relief boot;

FIG. 44 shows a perspective view of an backbone assembly of the fiberoptic connector of FIG. 43 with the bayonet and a compression springremoved for clarity; and

FIG. 45 shows a partial perspective view of the fiber optic connectorand bayonet of FIG. 43 being slid into engagement with an exemplaryST-type receptacle.

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 1-3 show an exemplary re-terminable fiber optic connector 10 inexploded, assembled and cross-sectional views. Connector 10 includes abayonet 100, cam 200, backbone 300, retaining nut 400, strain reliefboots 500, compression spring 600, ferrule holder 700, cam plank 800,Vee-plank 900, optical fiber stub 1000, and ferrule 1100. Connector 10is designed to be terminated, for example, using either buffered opticalfiber or jacketed optical fiber cable with an aramid fiber strengthmember. This particular exemplary optical connector is a no-crimp designin which rotation of cam 200 is used to activate or deactivatetermination of the fiber in the connector. Rotation is preferablyachieved using a cam activation tool, an example of which will bedescribed later with reference to FIGS. 27-40.

Bayonet 100 provides a gripping surface for users while also retainingbackbone 300 and spring 600. Bayonet 100 latches to a mating adapter(unshown) as known in the art. Cam 200 retains spring 600 and provides acam surface for cam plank 800 that urges cam plank 800 toward and awayfrom Vee-plank 900 to terminate or release optical fiber stub 1000 andan optical fiber end therebetween. Cam 200 also may include an interfacesurface for mating with an activation tool.

Backbone 300 retains bayonet 100 and is threadably connectable toretaining nut 400 to retain an aramid strength member from jacketedfiber optic cabling therebetween as known in the art. Backbone 300preferably includes snap features to retain both cam 200 and ferruleholder 700. A front end of retaining nut 400 includes threads that matewith backbone 300. A rear end of retaining nut 400 retains a suitablestrain relief boot 500. Strain relief boot 500 provides strain reliefand minimum bend radius control to the optical fiber received withinconnector 10. Compression spring 600 provides axial force to matedferrule 1100 end faces during a mating condition.

Ferrule holder 700 serves several functions. Ferule holder 700 retainscam plank 800 and Vee-plank 900 therein so that when terminated, camplank 800 and Vee-plank 900 are urged together to clamp and retainoptical fiber stub 1000 and a length of optical fiber therebetween.Ferrule holder 700 also provides keyed positioning relative to anadapter and serves to align the ferrule 1100 within the ferrule holder700. Additionally, ferrule holder 700 serves as a bearing surface forrotation of cam 200.

The optical fiber stub 1000 guides light and serves as an interface witha mating fiber optic element when suitably abutted. Ferrule 1100 isprovided to align the optical fiber stub 1000 as known in the art.

Various sub-components of the exemplary optical connector 10 will bedescribed with reference to FIGS. 4-17. FIG. 4 shows details of ferruleholder 700. Ferrule holder 700 includes a ferrule alignment pocket 705on a first end that aligns and fixes ferrule 1100. An adhesive pocket710 receives adhesive for bonding of the ferrule 1100 to the ferruleholder 700. An alignment key 720 extends radially outward from ferruleholder 700 near the one end and provides a radial alignment elementrelative to a mating adapter. A forward bearing surface 730 is providednear the first end that provides a first bearing surface for cam 200. Arear bearing surface 760 is provided rearward of forward bearing surface730 that provides an additional bearing surface for cam 200. The bearingsurfaces minimize radial misalignment of the cam.

A rib slot 740 is provided intermediate ends of ferrule holder 700 forpositioning and retaining a cam plank rib provided on cam plank 800while cam plank 800 and Vee-plank 900 are movably retained within aplank pocket 750. A buffer clamp 770 includes a lever arm that is biasedto extend slightly above the outer circumference of ferrule holder 700to retain a fiber buffer. An alignment flat 780 is provided on a portionof the ferrule holder circumference near an opposite second end of theferrule holder. Alignment flat 780 prevents axial rotation of ferruleholder 700 relative to backbone 300. Alignment flat 780 mates parallelwith a backbone alignment flat 340 (FIG. 11). An annular snap groove 790is provided near the second end that axially retains and positions theferrule holder 700 to backbone 300 by retention of backbone annular snap330 (FIG. 11).

In prior designs, the alignment key was located on the cam. Because ofthis, it was possible that the connector cam could be de-activated whenthe connector was mated into an adapter because the backbone was free torotate. Thus, if an end user held onto and rotated the backbone, the camwould de-activate. However, this exemplary design prevents camde-activation when the connector is mated to an adapter. This isachieved by locating the alignment key 720 on the ferrule holder 700rather than the cam. The ferrule holder 700 is prevented from rotatingbecause the alignment key 720 engages in an adapter slot. Moreover, thebackbone 300 and the ferrule holder 700 are fixed relative to each otherby backbone alignment flat 340 and ferrule holder alignment flat 780.Because the ferrule holder 700 prevents backbone 300 from rotating andthe cam 200 is unexposed, cam 200 cannot be de-activated when matingwith an adapter. That is, because no part of cam 200 is exposed whenconnector 10 is mated in the adapter, it is not possible to rotate thecam relative to the other parts. This ensures positive activation of thecam.

FIGS. 5-8 show details of cam 200. Cam 200 is provided with anactivation cutout 210 that interfaces with a cam activation tool to bedescribed later. Activation cutout 210 also provides clearance for theferrule holder alignment key 720 during cam activation. Cam activationcutout 210 allows for limited rotation of ferrule holder 700 (such as90°). In particular, cutout 210 limits motion of alignment key 720. Thecutout 210 also serves as an interface between cam 200, ferrule holder700, and a cam activation tool. A forward bearing surface 220 and rearbearing surface 240 provide bearing surfaces for ferrule holder 700.This minimizes radial misalignment of ferrule holder 700.

The interior of cam 200 includes a plank cam profile 230 as best shownin FIGS. 6-7 near a first end of cam 200. Cam profile 230 provides acamming surface for the cam plank rib 850 (FIG. 13). A buffer clamp camprofile 250 is provided near an opposite second end of cam 200 andprovides a camming surface for buffer clamp 770 (FIG. 4).

An annular snap groove 260 axially positions and retains backbone 300,by retaining backbone cantilever snap 350 (FIG. 11). The second end alsoincludes detent stops 270 and detent ramp 280. Detent stops 270 limitrotation of cam 200 during cam rotation while detent ramp 280 limitsrotation of cam 200 during normal connector use and allows rotation ofcam 200 during cam activation. The detent features thus allow retentionof cam 200 within backbone 300 while also having a built-in stop featureof a suitable limit, such as 90°.

FIG. 9 shows a perspective partial cross-sectional view of an exemplarybayonet 100. Bayonet 100 includes a grip region 110 formed from knurledor ribbed elements extending around a portion of the periphery ofbayonet 110. A retaining flange 120 is provided on the interior ofbayonet 100 and retains the backbone 300 and spring 600. A latch 130secures the connector to an adapter by latching to adapter pins as knownin the art. Latch areas may be bridged to provide additional retentionstrength to the latches when mated to an adapter.

FIGS. 10-11 show details of an exemplary backbone 300. Backbone 300includes anti-rotation flat 310, which prevents axial rotation ofbackbone 300 during cam activation by locking elements 300 and 700 inthe same rotation. Threads 320 are provided on one end of backbone 300and mate with retaining nut 400. An aramid strength member may beretained between the nut and backbone when the nut 400 is threaded ontothe backbone. An annular snap 330 axially retains and positions ferruleholder 700 relative to backbone 300 and is seated in annular snap groove790 of ferrule holder 700 (FIG. 4). Alignment flat 340 prevents axialrotation of backbone 300 relative to ferrule holder 700 and mates withalignment flat 780 of ferrule holder 700. Cantilever snaps 350 axiallyretain and position cam 200 relative to backbone 300 and provides adetent surface that limits cam rotation. Bayonet bearing surface 360provides axial positioning of bayonet 100.

FIG. 12 shows details of an exemplary retaining nut 400. FIG. 13 showsdetails of an exemplary cam plank 800, which includes a protruding rib850. FIG. 14 shows details of an exemplary Vee-plank 900, which includesa central slot sized to receive optical fiber stub 1000 therein. FIG. 15shows details of an exemplary ferrule 1100. A suitable ferrule is theshown industry standard 2.5 mm diameter ferrule 1100. FIG. 16 shows anexemplary optical fiber stub 1000, a conventional short length of bareoptical fiber. FIG. 17 shows two different styles of strain reliefboots, which provide both strain relief and bend radius control for theoptical cable exiting the connector.

The components of optical connector 10 are assembled into varioussub-assemblies. FIGS. 18-19 show a fiber stub sub-assembly 1200consisting of optical fiber stub 1000 and ferrule 1100 in an assembledstate. A ferrule holder sub-assembly 1300 consists of cam plank 800,Vee-plank 900, ferrule holder 700, and fiber stub sub-assembly 1200.These parts are assembled as shown. In particular, cam plank 800 isinserted into ferrule holder 700 until cam plank rib 850 protrudesthrough slot 740 in ferrule holder 700. The Vee-plank 900 is theninserted into ferrule holder 700 such that the flat faces of both planks800, 900 are facing each other. The ferrule stub sub-assembly 1200 isthen attached to ferrule holder 700 through interference fit and/oradhesive as known in the art. In particular, the ferrule stubsub-assembly 1200 is pressed into pocket 710 of ferrule holder 700. Asuitable adhesive may be applied and allowed to cure in pocket 720around ferrule 1100 for additional retention force. Adhesive may also beapplied around ferrule 1100 before or during the press operation. Thisresults in the assembled components shown in FIG. 19.

FIGS. 20-21 show a cam sub-assembly 1400 consisting of cam 200,compression spring 600, bayonet 100, and backbone 300. Compressionspring 600 and bayonet 100 are captured between cam 200 and backbone300. Cam 200 and backbone 300 are axially fixed relative to each otherby suitable connection, such as snap fit. An exemplary connection methodinvolves placing compression spring 6 over the smaller cylindricalsurface of cam 200. Radial alignment between compression spring 600 andcam 200 is not necessary at this time. Bayonet 100 is then placed ontocam 200 such that the bayonet grips 110 are positioned axially oppositethe cam activation cutout 210. Radial alignment between bayonet 100 andcam 200 is not required at this time. Backbone 300 is then aligned withcam 200 such that the backbone threads 320 are positioned axiallyopposite cam activation cutout 210 and the backbone cantilever snap 350is radially aligned between cam detent stop 270 and detent ramp 280. Thebackbone 300 is then pushed axially toward cam activation cutout 210until the backbone cantilever snap 350 is positioned in the cam annularsnap groove 260. This results in preloading of compression spring 600between cam 200 and bayonet 100 and an assembly as shown in FIG. 21.

Final assembly of connector 10 is shown in FIGS. 22-23. Ferrule holdersub-assembly 1300 is axially and radially aligned with cam 200 of camsub-assembly 1400 such that the cam plank rib aligns with one of the twooffset cylindrical surfaces on the cam plank cam profile. The ferruleholder sub-assembly 1300 and cam sub-assembly 1400 are then relativelyfixed to each other when backbone 300 snap 330 locks into the ferruleholder annular snap groove 790.

A small amount of optical index matching gel may then be injected intothe ferrule holder assembly to fill the space between planks 800, 900and eliminate an air gap between the field and stub fibers.Alternatively, the gel can be added after the planks are installed inthe holder. Connector 10 is now ready for final termination and consistsof the connector assembly shown in FIG. 23, which upon termination willfurther include retaining nut and a strain relief boot.

A particular advantage to the illustrated connector design is that theferrule holder 700 is isolated from axial loads on the optical fibercable when the cable is mated in a suitable adapter. In this particularexample of an ST-type fiber optic connector, the adapter may be aFOCIS-2 (ST-type) adapter. This is desirable because the ferrule holder700 may experience high tensile stresses due to the small cross-sectionat the buffer clamp area 770. These axial loads are transmitted frombackbone 300 to cam 200 by cantilever snap 350 and annular snap groove260, from cam 200 to compression spring 600, from the compression spring600 to bayonet flange 120, from bayonet flange 120 to bayonet latch 130,and finally to the adapter (unshown).

Connector 10 is now ready for end user termination in field and ispositionable between a deactivated position (FIG. 24), through apartially activated position (FIG. 25), and a fully activated position(FIG. 26). As can be seen in these Figures, buffer clamps 770 move fromthe expanded and separated state of FIG. 24 to a compressed state inFIG. 26 that biases a buffer of an optical fiber therebetween to effecttermination. At this time, planks 800, 900 are urged towards each otherto bias and hold stub 1100 and an end section of optical fiber, with thefiber clamping first and the buffer generally clamping after the fiberis clamped.

One exemplary method of termination of the connector will now bedescribed. Connector 10 is positioned in a cam activation tool, such asthe one described in FIGS. 27-40 below. A length of jacketed opticalfiber cable or buffered fiber is then suitably stripped to expose ashort length of bare optical fiber followed by a short length ofbuffered fiber as is known. The fiber is then cleaved using anyconventional cleaving device to provide an end face that is nearperpendicular to the axis of the fiber. The cleaved fiber is theninserted into the back opening of ferrule holder 700. Cam plank 800 andVee-plank 900 are initially spaced apart and guide the fiber into thegroove of Vee-plank 900 as the fiber is pushed toward ferrule 1100.Eventually, the fiber butts against the end of optical fiber stub 1000and the buffer is positioned between ferrule holder 700 and ferruleholder buffer clamps 770. Ferrule holder 700 and backbone 300 are thenheld in a fixed position while cam 200 is rotated by 90°counter-clockwise relative to ferrule holder 700 as shown in FIG. 23.Connector 10 is then positioned in a cam activation tool, such as theone described in FIGS. 27-40 below.

In particular, connector 10 is seated in the tool so that backboneanti-rotation flats 310 are positioned in a slot on the tool that holdthe backbone in a fixed position. A tool feature that engages the camactivation cutout is rotated 90° counter-clockwise to activate theconnector cam mechanism.

The two cam surfaces 230 and 250 are timed so that plank cam profile 230engages and clamps the fibers generally before the buffer clamp camprofile 250 engages and clamps the buffer. As cam 200 is rotated, camplank profile 230 pushes against the cam plank rib 850. The cam plank800 pushes against the Vee-plank 900, which is supported inside ferruleholder 700. The optical fiber stub and field fiber are clamped betweenthe cam plank 800 and Vee-plank 900. Shortly after the cam plank profile230 engages the cam plank 800 and the cam buffer clamp cam profile 250forces the buffer clamps 770 on the ferrule holder 700 towards eachother to capture the fiber buffer.

One backbone cantilever snap 350 deflects as it slides over cam detentramp 770 and abuts cam detent stop 280 (FIGS. 24-26) to prevent furtherrotation of cam 200. The cam detent stop 280 provides a positive stop toensure proper cam engagement. The cam detent ramp 270 preventsaccidental disengagement of cam 200 during use. The process isreversible when sufficient force is applied in a clockwise directionsuch that backbone cantilever snap 350 deflects and slides over camdetent ramp 270. FIG. 24 shows a de-activated cam. FIG. 25 shows the camat mid-activation. FIG. 26 shows a fully activated cam.

Strain relief boots 500 are used to provide strain relief and control ofthe bend radius of the optical fiber. A strain relief boot used forbuffered fiber is attached by an interference fit between the boot andthe backbone threads 320. A strain relief boot used for jacketed opticalfiber cable is attached by an interference fit between the boot 500 andthe retaining nut 400 that has been threaded onto the backbone threads320.

In the illustrated embodiment, connector 10 is an ST-type connector.However, the invention is not limited to this and may take other formsof no-crimp fiber optic connector.

An exemplary cam activation tool 20 for use in terminating connector 10will be described with reference to FIGS. 27-33. Tool 20 mates withfiber optic connector 10 and rotates to activate a cam mechanism, suchas cam 200, of the connector through a grip portion, such as a lever, toterminate a fiber without a crimp. Tool 20 thus allows the connectortermination to be reversed.

Tool 20 includes a base 1500 and a cam activation tool handle 1600. Toolbase 1500 is provided to position and support connector 10 and camactivation tool handle 1500. The tool engages with the connector ferruleholder to prevent rotation and engages with the connector backbone toprevent rotation. The cam activation tool handle 1600 then engages withthe connector, rotates the connector cam, and provides a grippingsurface for improved handling of the tool.

Specific details of an exemplary base 1500 are shown in FIG. 28. Base1500 includes a base plate 1560, a tool handle retaining arm and twoupstanding cradle members. Base plate 1560 may be mounted on a suitablesupport surface, or form part of another tool, such as an Opti-Camtermination tool 40 (FIG. 40). The retainer arm 1590 is arcuate anddefines a semi-cylindrical bearing surface 1520 and rotation stops 1510.Because tool 20 is made from a plastic or other partially resilientmaterial, there is an amount of bending that allows for insertion ofhandle 1600 into the bearing surface 1520. This allows for a snap-fitconnection of handle 1600 through the opening defined by rotation stops1510 and rotatable retention within bearing surface 1520 delimited bystops 1510. Bearing surface 1520 interfaces with an outer circumferenceof tool handle 1600 and minimizes axial misalignment of the toolrelative to the base. A rear surface of the retaining arm forms analignment face that axially positions the cam activation tool handle1600 during use.

A first upstanding member forms an alignment pad 1580 that is positionedslightly rearward of the retaining arm 1590. Alignment pad 1580 includesan anti-rotation slot 1530 on a top surface thereof that engages withthe connector ferrule holder alignment key 730 to support or cradle theferrule holder and prevent rotation of the ferrule holder 700 during camactivation.

A second upstanding member forms a cradle or support for a rear end ofconnector 10 and includes anti-rotation flats 1540 and a guide post1550. Anti-rotation flats 1540 align the connector backbone 300 andprevent backbone 300 from rotating during cam activation. In particular,flats 1540 mate with corresponding flats 310 on backbone 300. Guide post1550 also engages with backbone 300 and prevents axial movement. This isachieved, for example, by guide post 1550 mating into slot 350 ofbackbone 300.

Details of an exemplary cam activation tool handle 1600 are shown inFIGS. 29-30. Handle 1600 includes a circular shape that defines an outerbearing surface 1620 and an inner through hole 1650. A grip portion 1610serves as a gripping surface for activation (rotation) of the cam toolhandle by an end user. An exemplary grip is lever 1610, which extendsradially outward from the handle. Because of the relatively small sizeof the tool and connectors being terminated, such as about a 7/16″diameter base and a lever 1610 height of about ¼″, the lever isparticularly useful in providing sufficient height and leverage toeffect rotation of the tool handle and activation of the connector cam.An alignment flange 1640 is provided on one side of the tool handle.Flange 1640 extends radially beyond the outer circumference of the toolhandle bearing surface 1620 and serves to prevent axial movement of thecam activation tool 1600 during use by closely fitting between basealignment face 1170 and alignment pad 1180. Through hole 1650 providesclearance for receipt of portions of connector ferrule 1100 therethroughand clearance for a patch cord, such as a VFL patch cord 30 (FIG. 40).Through hole 1650 includes a cam interface 1630 that interfaces andmates with connector cam 200 to provide a structure that enablesactivation and de-activation of the cam 200 by having a profile thatmatches that of cam 200 so that the two elements rotate together.

Cam activation tool 20 is assembled as shown in FIGS. 31-33. First, camactivation tool handle 1600 is placed near retaining arm 1590. Alignment1640 is then axially aligned between base alignment face 1570 andalignment pad 1580. Lever 1610 is then radially aligned to extendbetween the two rotation stops 1510 as shown in FIG. 31. Then, toolhandle 1600 is snap fit into the retaining arm 1590 so that the bearingsurface 1520 surrounds tool handle 1600 and the retaining arm 1590deflects or snaps back to its original position to retain tool handle1600 therein as shown in FIGS. 32-33.

Use of the tool 20 to terminate an optical fiber connector will bedescribed with reference to FIGS. 34-40. Referring to FIG. 34, cam lever1610 is positioned to a first position, such as against one stop 1510 inthe vertical position as shown. This is the default de-activationposition. An assembled optical connector 10 such as the one described inFIGS. 1-26 is then placed in the tool 20. In particular, ferrule 1100 ofconnector 10 is inserted into through hole 1650 as shown in FIG. 34.Connector 10 is then rotated and aligned so that the ferrule holderalignment key 730 fits within anti-rotation slot 1530 of base 1500. Thecam activation tool interface 1630 then is engaged with the camactivation cutout 210. Then, backbone 300 of connector 10 is positionedon the tool so that its anti-rotation flats 310 are aligned with theanti-rotation flats 1540 of base 1500. The connector backbone 300 nowfits around guide post 1550 to prevent axial movement relative to base1500 as shown in FIG. 35.

At this point, the connector is ready for maintaining forward pressure.Field termination can be achieved by stripping of an optical fiber andinsertion of the fiber into the connector 10. Then, a VFL patch cord 30(FIG. 40) may be mated to the ferrule 110 protruding through the tool'sthrough hole 1650.

Termination (activation) is achieved by holding of the base 1500 of thetool and rotating the cam activation tool handle lever 1610 from thefirst de-activation position shown in FIG. 36 to the rotated activationposition shown in FIG. 37, which is parallel to base plate 1560.Rotation of lever 1610 is stopped at the rotated position by stop 1510.Ferrule holder 700 and backbone 300 are held fixed relative to base 1500by the anti-rotation slot 1530 engaging with alignment key 730, baseanti-rotation flats 1540 engaging with backbone anti-rotation flats 340,and guide post 1550 engaging with backbone 300. However, because of theinterface between cam activation tool interface 1530 and the connectorcam activation cutout 210, the connector cam 200 rotates with rotationof tool portion 1600. Thus, rotation of tool handle 1600 results inrelative rotation of cam 200 relative to ferrule holder 700 and backbone300. This completes activation of the cam and pressing of the opticalfiber stub 1000 between planks 800, 900 as shown in FIG. 26.

To remove connector 10 from the tool, backbone 300 is first lifted offof base guide post 1550 and then the connector is slid back out of thetool.

Because there is no crimp for termination, this type of connector iscapable of reversing the activation process to allow removal of theoptical fiber, should the need arise. For example, in the event of apoor termination, improper alignment, or fiber breakage. This isachieved by placing the lever 1610 in the horizontal, activatedposition. Then, the connector is inserted into tool 20 so again the camactivation cutout 210 fits into the cam tool interface 1630 as describedabove. Then, the ferrule holder alignment key 720 and backbone 300 arepositioned as described previously. Cam activation lever 1610 is thenrotated upwards back to the first, vertical de-activation position. Stop1510 limits rotation of the lever. The connector cam 200 has now beenrotated by 90° relative to the ferrule holder 700 and backbone 300 toallow removal of the optical fiber from the connector and subsequentre-termination of another optical fiber, if desired.

The exemplary embodiments set forth above are intended to beillustrative and not limiting. For example, although the cam activationtool 20 can be used alone for connector activation, cam activation tool20 can also form part of a termination tool 40, such as an Opti-Camtermination tool shown in FIG. 40. In the FIG. 40 embodiment, base 1500would be integrated into or otherwise affixed to termination tool 40. AVFL patchcord 30 is connectable between termination tool 40 and anactivated or terminated electrical connector to test the termination.

In accordance with another embodiment illustrated in FIGS. 41-45, are-terminable ST-type fiber optic connector assembly is provided that issimilar to previous embodiments. However, this embodiment includes anadditional feature to prevent rotation of the bayonet relative to theconnector system when it is not installed in a corresponding ST-typereceptacle. This is particularly advantageous to enhance thefunctionality of an OptiCam ST connector, but may also be used in otherST-type connectors.

FIG. 41 shows a bayonet 2100 for an ST-type fiber optic connector 2000to be described later with reference to FIG. 43. Bayonet 2100 includes aknurled outer portion and an interior opening that includes a pluralityof bayonet anti-rotation flats 2110 that are preferably opposed to oneanother. Bayonet flats 2110 are oriented to mate with correspondingbackbone anti-rotation flats 2310 provided on backbone 2300 (FIG. 44).Bayonet 2100 also includes a bayonet retaining flange 2120 (FIG. 42).

Backbone 2300 is oriented so that backbone flats 2310 are aligned withand parallel to the bayonet anti-rotation flats 2110. This allows afront surface 2320 of the backbone to extend between the flats 2110 andagainst the bayonet retaining flange 2120. Contact between the frontsurface 2320 and the retaining flange 2120 is maintained by pressureexerted by the compression spring (unshown). This mechanically alignsthe backbone 2300 with a connector system key 2720 provided on a ferruleholder 2700 (FIG. 43) and with bayonet 2100 to prevent relativerotation. The ferrule holder 2700 and the backbone 2300 have theirorientation maintained fixed as described in earlier embodiments.

In certain designs, such as in the FIG. 1 embodiment, the end user gripsthe portion of the backbone that protrudes from the bayonet whilescrewing on the strain relief boot. However, the limited amount ofbackbone exposure makes it difficult to obtain a good grip by fingersalone. The user cannot grip the bayonet alone because the bayonet inthis embodiment is allowed to spin relative to the backbone. Therefore,it may be difficult to thread and tighten the strain relief boot ontothe backbone.

This potential problem is solved in the illustrated embodiment of FIGS.41-45 by mechanically aligning and restraining movement of the backbone2300 relative to the bayonet 2100. Thus, a user may now readily grip thebayonet 2100 while screwing the strain relief boot 2500. This designprovides significantly more surface area to grip (i.e., the entirebayonet surface area) to perform such an operation and does not resultin an inadvertent rotation of the bayonet 2100.

Also in certain designs, such as the FIG. 1 embodiment, an end user hasto align the bayonet to ST receptacle latching studs, such as studs 2820in FIG. 45. However, when inserting a typical ST connector system into aST receptacle 2800, the end user must first rotate the connector systemaxially until the connector system key is aligned with the ST receptaclealignment slot. The user then has to insert the connector system furtherinto the ST receptacle until the bayonet contacted the ST receptaclelatching studs. The user then rotates the bayonet axially until bayonetclearance slots are aligned with the latching studs before the bayonetcan be latched to the ST receptacle. This somewhat cumbersome operationcan be simplified by the embodiment of FIGS. 41-45.

One benefit to maintaining the alignment of the backbone 2300 to theconnector system key 2720 as described in FIGS. 41-45 is that bayonetclearance slots 2130 (FIG. 43) are already aligned to latching studs2820 of ST receptacle 2800 once the connector system key 2720 is alignedto alignment slots 2810 of the ST receptacle 2800 (FIG. 45). Thissimplifies the insertion of the connector system into the receptacle.

An additional feature of the FIG. 41-45 embodiment is that during thelatching operation, bayonet 2100 is biased toward ST receptacle 2800 bythe internal compression spring. This allows the backbone anti-rotationflats 2310 to disengage from the bayonet anti-rotation slots 2110,allowing bayonet 2100 to rotate axially and latch to the ST receptacle2800. The process also works in reverse during unlatching so that whenthe connector system is unlatched and removed from the ST receptacle2800, the anti-rotation flats 2110 on bayonet 2100 align with theanti-rotation flats 2310 on the backbone 2300.

Various changes can be made without departing from the spirit and scopeof the appended claims. Therefore, the connectors, activation tools andassembly methods described are intended to embrace all known, orlater-developed, alternatives, modifications, variations, and/orimprovements.

1. A reversibly terminable stub fiber connector and tool assemblycomprising: a termination tool, the tool having a base, a firstupstanding cradle member, and a tool handle that is rotatable relativeto the base; and a stub fiber connector, the connector having a ferruleholder and a cam enclosing the ferrule holder, wherein the firstupstanding cradle member is configured to engage the ferrule holder suchthat the ferrule holder is fixed in rotation relative to the base andthe tool handle is configured to engage the cam such that the cam isfixed in rotation to the tool handle, wherein the ferrule holder has analignment key and the first upstanding cradle member engages thealignment key.
 2. The assembly of claim 1 wherein the cam comprises acutout and the tool handle comprises a through-hole, the through-hole ofthe tool handle being configured to engage the cutout of the cam.
 3. Theassembly of claim 2 wherein the base further comprises rotation stopsconfigured to limit the rotation of the tool handle relative to thebase.
 4. The assembly of claim 3 further comprising a pair of planks,the planks being enclosed within the ferrule holder, the cam configuredto provide a compressive force on at least a portion of one of theplanks when the cam is rotated relative to the ferrule holder.
 5. Theassembly of claim 4 wherein the tool further comprises a secondupstanding cradle member and wherein the connector further comprises abackbone fixed in rotation relative to the ferrule holder, the secondupstanding cradle member being configured to support the backbone. 6.The assembly of claim 5 wherein the connector further comprises abayonet.